hearing BOV when disengaging cruise?

[T is for TURBO]

So i was on my way to work, and I had my Cruise control set at about 65-70, and when i got to my exit, I turned the cruise off to coast down the ramp and as soon as i turned off the cruise, I heard my BOV. Now I know I wasn't in boost, i was at about 11 inches of vac at like i sad, 65 or so. Also, I hear it go off sometimes when accelorating real slow (not going into boost, 1 inch/vac, or 0) and let off the gas to shift. When i hear it, its just a light whistle, and can only hear it when the windows are down... My question is why its doing this?
The only theory is that when the throttle is let off, the BOV is actuated by the vaccum, and the sound I am hearing is simply a slight pressure change in IC piping and since I have an aftermarket BOV it is more audible?

Can anyone fill me in?
THANKS!
Shawn

 

[blackGSX2g]

Yes, that is correct...even though you are in vaccum, there is still air moving in your IC pipes. Since the pressure change occurs at the intake manifold first, it releases the valve. I can hear mine when I let off the gas at pretty much any point.

 

[T is for TURBO]

Thanks a lot man for the info!

 

[trbotaln]

If your BOV is adjustable, then you might have the spring set to soft.

 

[99gst_racer]

If your BOV is adjustable, then you might have the spring set to soft.

Yup, that's correct. ^^^^
And the way to find out if it is too soft, it by doing a boost leak test and pressurizing your pipes to the amount of boost you are running. (something I'll actually be doing in about 2 hrs. )